V3SlotSetters linter/codemod draft

docs/CHANGELOG.md

@@ -76,6 +76,15 @@ nav_order: 5
 
     *Reegan Viljoen*
 
+* Add codemod to detect and migrate deprecated Slots setters to new `with_*` prefix introduced in v3.x. Note: This codemod is non-deterministic and works on a best-effort basis.
+
+    ```bash
+    bin/rails view_component:detect_legacy_slots
+    bin/rails view_component:migrate_legacy_slots
+    ```
+
+    *Hans Lemuet, Kirill Platonov*
+
 ### v3.0.0
 
 1,000+ days and 100+ releases later, the 200+ contributors to ViewComponent are proud to ship v3.0.0!

lib/tasks/view_component.rake

@@ -0,0 +1,15 @@
+require "view_component/codemods/v3_slot_setters"
+
+namespace :view_component do
+  task detect_legacy_slots: :environment do
+    ARGV.each { |a| task a.to_sym {} }
+    custom_paths = ARGV.compact.map { |path| Rails.root.join(path) }
+    ViewComponent::Codemods::V3SlotSetters.new(view_path: custom_paths).call
+  end
+
+  task migrate_legacy_slots: :environment do
+    ARGV.each { |a| task a.to_sym {} }
+    custom_paths = ARGV.compact.map { |path| Rails.root.join(path) }
+    ViewComponent::Codemods::V3SlotSetters.new(view_path: custom_paths, migrate: true).call
+  end
+end

lib/view_component/codemods/v3_slot_setters.rb

@@ -0,0 +1,220 @@
+# frozen_string_literal: true
+
+module ViewComponent
+  # Usage:
+  #
+  # Run via rake task:
+  #
+  #     bin/rails view_component:detect_legacy_slots
+  #     bin/rails view_component:migrate_legacy_slots
+  #     bin/rails view_component:migrate_legacy_slots app/views
+  #
+  # Or run via rails console if you need to pass custom paths:
+  #
+  #     ViewComponent::Codemods::V3SlotSetters.new(
+  #       view_path: Rails.root.join("app/views"),
+  #     ).call
+  module Codemods
+    class V3SlotSetters
+      TEMPLATE_LANGUAGES = %w[erb slim haml].join(",").freeze
+      RENDER_REGEX = /render[( ](?<component>\w+(?:::\w+)*)\.new[) ]+(do|\{) \|(?<arg>\w+)\b/ # standard:disable Lint/MixedRegexpCaptureTypes
+
+      Suggestion = Struct.new(:file, :line, :message)
+
+      def initialize(view_component_path: [], view_path: [], migrate: false)
+        Rails.application.eager_load!
+
+        @view_component_path = view_component_path
+        @view_path = view_path
+        @migrate = migrate
+      end
+
+      def call
+        puts "Using ViewComponent path: #{view_component_paths.join(", ")}"
+        puts "Using Views path: #{view_paths.join(", ")}"
+        puts "#{view_components.size} ViewComponents found"
+        puts "#{slottable_components.size} ViewComponents using Slots found"
+        puts "#{view_component_files.size} ViewComponent templates found"
+        puts "#{view_files.size} view files found"
+        process_all_files
+      end
+
+      def process_all_files
+        all_files.each do |file|
+          process_file(file)
+        end
+      end
+
+      def process_file(file)
+        @suggestions = []
+        @suggestions += scan_exact_matches(file)
+        @suggestions += scan_uncertain_matches(file)
+
+        if @suggestions.any?
+          puts
+          puts "File: #{file}"
+          @suggestions.each do |s|
+            puts "=> line #{s.line}: #{s.message}"
+          end
+        end
+      end
+
+      private
+
+      def scan_exact_matches(file)
+        [].tap do |suggestions|
+          rendered_components = []
+          content = File.read(file)
+
+          if (render_match = content.match(RENDER_REGEX))
+            component = render_match[:component]
+            arg = render_match[:arg]
+
+            if registered_slots.key?(component.constantize)
+              used_slots_names = registered_slots[component.constantize]
+              rendered_components << {component: component, arg: arg, slots: used_slots_names}
+            end
+          end
+
+          File.open(file, "r+") do |f|
+            lines = []
+            f.each_line do |line|
+              rendered_components.each do |rendered_component|
+                arg = rendered_component[:arg]
+                slots = rendered_component[:slots]
+
+                if (matches = line.scan(/#{arg}\.#{Regexp.union(slots)}/))
+                  matches.each do |match|
+                    new_value = match.gsub("#{arg}.", "#{arg}.with_")
+                    message = if @migrate
+                      "replaced `#{match}` with `#{new_value}`"
+                    else
+                      "probably replace `#{match}` with `#{new_value}`"
+                    end
+                    suggestions << Suggestion.new(file, f.lineno, message)
+                    if @migrate
+                      line.gsub!("#{arg}.", "#{arg}.with_")
+                    end
+                  end
+                end
+              end
+              lines << line
+            end
+
+            if @migrate
+              f.rewind
+              f.write(lines.join)
+            end
+          end
+        end
+      end
+
+      def scan_uncertain_matches(file)
+        [].tap do |suggestions|
+          File.open(file, "r+") do |f|
+            lines = []
+            f.each_line do |line|
+              if (matches = line.scan(/(?<!\s)\.(?<slot>#{Regexp.union(all_registered_slot_names)})\b/))
+                matches.flatten.each do |match|
+                  next if @suggestions.find { |s| s.file == file && s.line == f.lineno }
+
+                  message = if @migrate
+                    "replaced `#{match}` with `with_#{match}`"
+                  else
+                    "maybe replace `#{match}` with `with_#{match}`"
+                  end
+                  suggestions << Suggestion.new(file, f.lineno, message)
+                  if @migrate
+                    line.gsub!(/(?<!\s)\.(#{match})\b/, ".with_\\1")
+                  end
+                end
+              end
+              lines << line
+            end
+
+            if @migrate
+              f.rewind
+              f.write(lines.join)
+            end
+          end
+        end
+      end
+
+      def view_components
+        ViewComponent::Base.descendants
+      end
+
+      def slottable_components
+        view_components.select do |comp|
+          comp.registered_slots.any?
+        end
+      end
+
+      def registered_slots
+        @registered_slots ||= {}.tap do |slots|
+          puts
+          puts "Detected slots:"
+          slottable_components.each do |comp|
+            puts "- `#{comp}` has slots: #{comp.registered_slots.keys.join(", ")}"
+            slots[comp] = comp.registered_slots.map do |slot_name, slot|
+              normalized_slot_name(slot_name, slot)
+            end
+          end
+        end
+      end
+
+      def all_registered_slot_names
+        @all_registered_slot_names ||= registered_slots.values.flatten.uniq
+      end
+
+      def view_component_files
+        Dir.glob(Pathname.new(File.join(view_component_path_glob, "**", "*.{rb,#{TEMPLATE_LANGUAGES}}")))
+      end
+
+      def view_files
+        Dir.glob(Pathname.new(File.join(view_path_glob, "**", "*.{#{TEMPLATE_LANGUAGES}}")))
+      end
+
+      def all_files
+        view_component_files + view_files
+      end
+
+      def view_component_paths
+        @view_component_paths ||= [
+          Rails.application.config.view_component.view_component_path,
+          @view_component_path
+        ].flatten.compact.uniq
+      end
+
+      def view_component_path_glob
+        return view_component_paths.first if view_component_paths.size == 1
+
+        "{#{view_component_paths.join(",")}}"
+      end
+
+      def rails_view_paths
+        ActionController::Base.view_paths.select do |path|
+          path.to_s.include?(Rails.root.to_s)
+        end.map(&:to_s)
+      end
+
+      def view_paths
+        @view_paths ||= [
+          rails_view_paths,
+          Rails.application.config.view_component.preview_paths,
+          @view_path
+        ].flatten.compact.uniq
+      end
+
+      def view_path_glob
+        return view_paths.first if view_paths.size == 1
+
+        "{#{view_paths.join(",")}}"
+      end
+
+      def normalized_slot_name(slot_name, slot)
+        slot[:collection] ? ActiveSupport::Inflector.singularize(slot_name) : slot_name.to_s
+      end
+    end
+  end
+end

test/sandbox/app/helpers/aliases_helper.rb

@@ -0,0 +1,7 @@
+# frozen_string_literal: true
+
+module AliasesHelper
+  def sandbox_slots(*args, **kwargs, &block)
+    render SlotsComponent.new(*args, **kwargs), &block
+  end
+end

test/sandbox/app/views/codemods/_v2_slots_setters_alias.html.erb

@@ -0,0 +1,5 @@
+<%= sandbox_slots do |component| %>
+  <% component.subtitle do %>
+    <small>This is my subtitle!</small>
+  <% end %>
+<% end %>

test/sandbox/app/views/codemods/_v2_slots_setters_exact.html.erb

@@ -0,0 +1,14 @@
+<%= render SlotsComponent.new do |component| %>
+  <% component.title do %>
+    This is my title!
+  <% end %>
+<% end %>
+
+<%= render SlotsComponent.new do |component| %>
+  <% component.tab do %>
+    <h1>Tab A</h1>
+  <% end %>
+  <% component.tab do %>
+    <h1>Tab B</h1>
+  <% end %>
+<% end %>

test/sandbox/app/views/integration_examples/empty_slot.slim

@@ -1,3 +1,3 @@
 = render(EmptySlotComponent.new) do |component|
-  - component.title
+  - component.with_title
     - nil

test/sandbox/test/codemods/v3_slot_setters_test.rb

@@ -0,0 +1,57 @@
+# frozen_string_literal: true
+
+require "test_helper"
+require "view_component/codemods/v3_slot_setters"
+
+class V3SlotSettersTest < Minitest::Test
+  def teardown
+    restore_legacy_slots
+  end
+
+  def test_detects_legacy_slots
+    output = capture_output do
+      ViewComponent::Codemods::V3SlotSetters.new.call
+    end
+
+    assert_match "_v2_slots_setters_exact.html.erb\n=> line 2: probably replace `component.title` with `component.with_title`", output
+    assert_match "line 8: probably replace `component.tab` with `component.with_tab`", output
+    assert_match "line 11: probably replace `component.tab` with `component.with_tab`", output
+    assert_match "_v2_slots_setters_alias.html.erb\n=> line 2: maybe replace `subtitle` with `with_subtitle`", output
+  end
+
+  def test_migrate_legacy_slots
+    ViewComponent::Codemods::V3SlotSetters.new(migrate: true).call
+
+    output = capture_output do
+      ViewComponent::Codemods::V3SlotSetters.new.call
+    end
+
+    refute_match "_v2_slots_setters_exact.html.erb\n=> line 2: probably replace `component.title` with `component.with_title`", output
+    refute_match "line 6: probably replace `component.tab` with `component.with_tab`", output
+    refute_match "line 9: probably replace `component.tab` with `component.with_tab`", output
+    refute_match "_v2_slots_setters_alias.html.erb\n=> line 2: maybe replace `subtitle` with `with_subtitle`", output
+  end
+
+  private
+
+  def capture_output
+    original_stdout = $stdout
+    $stdout = StringIO.new
+    yield
+    $stdout.string
+  ensure
+    $stdout = original_stdout
+  end
+
+  def restore_legacy_slots
+    test_views = [
+      Rails.root.join("app/views/codemods/_v2_slots_setters_alias.html.erb"),
+      Rails.root.join("app/views/codemods/_v2_slots_setters_exact.html.erb")
+    ]
+    test_views.each do |file|
+      content = File.read(file)
+      content.gsub!("with_", "")
+      File.write(file, content)
+    end
+  end
+end